This invention relates generally to guards or shields for protecting operating personnel from contacting moving mechanical parts of machinery and more particularly to shielding rotating rolls in a bending machine.
Machines for bending a metal workpiece, i.e., structural sections, plates, etc., comprise coacting rotating rolls. The rolls are separted to form a bite into which the workpiece is introduced. Friction between the workpiece and the driven rolls causes the workpiece to be advanced through the gap or separation between the rolls to perform the desired operation on the workpiece. The bite area between the rolls is frequently unprotected against the accidental contact with operating personnel and/or their clothing.
A particular type of machine for forming metal plates into cylindrical articles as e.g. tank sections comprises three parallel rolls. Two of the rolls are disposed side by side and spaced apart. The third roll is disposed above the two lower rolls midway between them. The bite into which a plate is introduced is formed by the separation between the upper roll and one of the lower two rolls on the entry side. Plate bending machines are usually of substantial width having rolls greater than 6 feet in length. The exposed roll bite area is therefore quite extensive, presenting a hazard to operating personnel. Bending machines of this type have generally been void of protective shields.